"I'm absolutely glad they still do that and we still do that," said Rangers outfielder Jeff Baker, whose father spent 22 years in the Army and retired as a colonel. "The day we lose sight and forget is the day something happens again. I'm not concerned too much going forward about how we're going to respond, because I know the way they've responded for the last 10 years. I think baseball will always do the right thing."

San Francisco's Dean Crispen, a captain from Station 28, and firefighter Derek O'Leary, driver of rescue squad one from Station 1, were so hurt by the attacks that they boarded the first commercial flight available from San Francisco to New York that morning, used vacation time and purchased their own airline tickets to join a group of friends and coworkers in the rescue efforts.

Wednesday, they threw out ceremonial first pitches at AT&T Park, side by side.

With ceremonies across the country in all 15 parks, ballplayers, coaches and umpires wore American flag patches on their caps. Special lineup cards were used, while tributes were planned and flags flew at half-mast.

We Shall Not Forget was the theme portrayed across all the parks.

That message was especially poignant at New York's Citi Field, where Mets players honored New York City first responders by taking batting practice in hats representing the city's agencies. The Mets hosted several tributes in honor of 9/11 before and during their game against the Nationals, and players from both teams hosted a meet-and-greet with families from Tuesday's Children, a nonprofit organization committed to all children and individuals directly affected by the events of 9/11.

Among the guests at Citi Field on Wednesday was Kevin Gee, the father of Mets pitcher Dillon Gee. Kevin, a firefighter in Fort Worth, Texas, caught the first pitch.

"It's one of those dates in history where you're always going to know where you were, and you're going to remember what you felt like," Mets manager Terry Collins said. "As you go through life and you look back upon at a lot of things, a lot of times you don't really know how you felt. You'll always know how you felt on 9/11."

"I remember it like it was yesterday," Miami manager Mike Redmond said.

Redmond was still playing for the Marlins in 2001. The team had returned from a road trip, and the former catcher woke up to tend to his son, Ryan, who was then 6 months old.

"I was carrying him around the apartment, having some coffee," Redmond said. "I turned on TV. I remember that initially coming on. When the plane flew into the tower, I woke my wife up. I don't know if I will ever forget that day, and what happened."

The Marlins had a jersey with "Never Forget 9/11" printed on the back that they hung in their dugout.

White Sox pitcher Hector Santiago also has that day imprinted on his memory. Santiago was a 13-year-old eighth-grader at Luis Munoz Marin Middle School in Newark, N.J., from where he saw the World Trade Center towers go up in smoke.

"I know everybody has seen it on the news and stuff like that, but it's not like when you see it fall right there," Santiago said. "It's right in front of you and it's happening."

On Wednesday, Santiago was part of a group that served lunch to guests of the USO of Illinois at the Donnelly Armory on the South Side of Chicago, and he signed autographs and took pictures for individuals representing different military disciplines.

While Rays manager Joe Maddon wasn't near the site of any of the attacks, he has a personal connection to Sept. 11. Maddon's fraternity brother, Neil Levin, was the head of the New York Port Authority and was killed in the attacks. Maddon had recently reconnected with Levin and had talked to him about coming to a Yankees game when Maddon's Angels were in town, but it never happened.

"Whenever I hear 9/11, riding my bike today with the flag at half-mast," said Maddon, "I thought of Neil."

Jason Mastrodonato is a reporter for MLB.com. Follow him on Twitter @jmastrodonato.Andrew Simon is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.